This invention is directed to ostomy bags and more particularly to an ostomy bag with a novel multi-stage filter that resists contact contamination by semi-liquid waste collected in the bag.
Gases emitted from the stoma into an ostomy bag and gases that issue from waste material confined in the bag are usually deodorized before being evacuated from the bag. A deodorizing filter is generally located adjacent a gas outlet opening in the bag to ensure that the outward flow of gas from the bag passes through the deodorizing filter.
Most ostomy bags are normally worn for several days before the deodorizing capability of the filter begins to lose effectiveness. An ineffective or exhausted deodorizing filter can be replaced if the bag has provision for replaceable filters as in ostomy bags of U.S. Pat. No. 5,085,652. If there is no provision for filter replacement as in the ostomy bag of U.S. Pat. No. 5,074,851, the entire bag is often replaced when the deodorizing filter is no longer an effective deodorizer.
If the deodorizing filter is inadvertently contaminated by contact with waste material that accumulates in the bag, it may be desirable to replace the disposable bag immediately. Waste material contact with a deodorizing filter can occur as a result of physical activity by the wearer that, for example, shifts the contents of the bag toward the deodorizing filter, especially if such waste material is of a liquid or semi-liquid consistency.
Contact of the deodorizing filter with semi-liquid waste material will often clog the filter, thereby preventing adequate deodorization and evacuation of waste gas. Whenever a deodorizing filter is contaminated by contact with semi-liquid waste material and such contamination impedes the function of the deodorizing filter, the filter or bag should be replaced as soon as possible. The need for unexpected or accelerated replacement of deodorizing filters and/or ostomy bags because of contact contamination by waste is often at an inconvenience to the wearer.
Ostomy bag deodorizing filter contamination from contact with semi-liquid waste also commonly occurs when an individual is asleep or reclining and the ostomy bag is in a relatively horizontal orientation. In such instances of filter contamination, gas pressure is likely to build up in the bag because of a diminished rate of gas evacuation due to deodorizing filter clog. Occasionally pressure buildup in the bag will overcome the seal between the bag and the bag mounting surface. Once the seal between the bag and the mounting surface is broken, leakage of gas and other contents of the bag can occur, and if such leak or seal break is not detected, it can result in offensive odors as well as the soiling of an individual's garments.
It is thus desirable to provide an ostomy bag with a multi-stage filter system that prevents semi-liquid waste material from contaminating a deodorizing element but does not inhibit evacuation of gaseous waste through the deodorizing element.